The basic principle for a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) to display a frame of an image is inputting a square wave of a certain width to each row of pixels successively from top to bottom through a gate driving circuit for gating, then outputting the signal required by the row of pixels successively through a source driving circuit. At present, in a display device of such a structure, the gate driving circuit and the source driving circuit are generally connected on the glass panel through COF (Chip On Film) or COG (Chip On Glass) process. However, when the resolution is relatively high, there are more outputs at both the gate driving circuit and the source driving circuit, and the length of the driving circuit will also be increased. This is not benefit for the bonding process of the module driving circuit.
In order to overcome the above problem, the existing display device may adopt a GOA (Gate Drive On Array) circuit. Compared with the existing COF or COG processes, the GOA circuit not only saves the cost but also can achieve symmetrical design of both sides of the panel. Additionally, it can also save the bonding area of the gate driving circuit and the peripheral wiring space, thereby realizing narrow frame design of the display device, and improving capacity and yield of the display device. However, the existing GOA circuit also has certain problems. As shown in FIG. 1, there is a relatively large number of the thin film transistors (TFTs) in the existing GOA, so it occupies a relatively large space. In addition, since the existing circuit can only discharge the signal output end OUTPUT through the transistor M, the transistor M has a very large size, and occupies a relatively large space. Moreover, the control terminal voltage of the transistor M is the output of a certain stage of shift register unit below this shift register unit. Hence, the control terminal voltage value of the transistor M is a high level of the output voltage. However, since the high level is not high enough, the size of the transistor M has to be relatively large, it can be ensured that the output delay is within the range of the normal work, thereby also rendering the space occupied by the GOA circuit to be relatively large.